JP2002068799A - Filler for construction work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filler for construction work suitable for a back filling or landfilling material, developing no consolidation phenomenon, causing no ground subsidence and capable of easily crushing at repair work. SOLUTION: This filler for construction work includes a hard foamed resin such as hard polyurethane foam, cement, and aggregate that is added when necessary. The hard foamed resin content of the filler is about 10-90 vol.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filler for civil engineering work used for backfilling an excavated portion, reclaiming a landfill, filling a concrete pipe containing a large number of electric conduits therein, and the like.

[0002]

2. Description of the Related Art After digging below a road surface and completing predetermined construction work, when backfilling an excavated portion, the backfill is once performed using backfill soil, and traffic is temporarily restored. After opening, after a predetermined period of time, the work of adding backfill soil to a portion of the backfill soil that has subsided due to the consolidation phenomenon is performed, and the restoration is generally performed. Such a conventional method of backfilling an excavated portion is inconvenient in that the work of backfilling must be performed twice. In addition, in the state of the temporary restoration, there is an inconvenience that smooth running of the passing vehicle is hindered because unevenness is generated on the road surface due to land subsidence.

[0003] On the other hand, in the reclamation work on the shore and the like, since the earth and sand are deposited in the water, unexpected consolidation phenomenon and land subsidence due to the phenomenon are likely to occur, and the building constructed in the landfill is stably supported. To do so, means such as an adjustment jack may be required. Therefore, the construction period is prolonged and construction costs are increased.

[0004] On the other hand, although it is a field different from the above-mentioned backfilling and landfilling, as a material for fixing and protecting a conduit by filling a concrete tube containing a large number of conduits therein, foaming has conventionally been used. Mortar concrete is used. When filling the mortar concrete, use a firm fixture to fix the position of the conduit in the concrete tube in advance so that the conduit does not rise or deform due to the mortar concrete poured in. I have. Moreover, since mortar concrete has a large compressive strength and is hard to be crushed, once it is cast into a concrete pipe, it cannot be crushed thereafter and repaired. For this reason, as a material for filling the inside of the concrete pipe, it has sufficient strength to fix the position of the conduit pipe housed therein, does not require a fixing bracket, and can be easily crushed after filling. Materials are needed.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to prevent the occurrence of a consolidation phenomenon when used as a material for backfilling or landfilling.
There is no need to carry out additional construction due to land subsidence,
When excavation work is performed again, excavation is relatively easy, and when used as a filling material in concrete pipes, use fixing brackets for many conduits housed in concrete pipes. It is an object of the present invention to provide a filler for civil engineering work that can fix the position without causing deformation and that can be easily crushed at the time of repair.

[0006]

The filler for civil works according to the present invention is characterized by containing a hard foamable resin and cement. With this configuration, when used as backfill or landfill material in open-cutting work, etc.,
Because there is no consolidation phenomenon as seen in normal backfill soil, there is no need to take measures against ground subsidence, and construction can be completed at once, including hard foaming resin that can be easily crushed Therefore, the digging work can be easily performed even when the digging work or the like is performed again. In addition, when used as a landfill material for beaches, etc., by appropriately adjusting the compounding ratio of each material (the ratio of a hard foaming resin having a small specific gravity to a cement or aggregate having a large specific gravity), the entire filler can be adjusted. For example, 1.
It can be adjusted to 1 to 1.3, thereby minimizing the amount of cement or the like used. Furthermore, when used as a filler in a pipeline, since it contains a hard foaming resin that can be easily crushed, it is easy to crush the filler and form a gap in the pipeline during repair. it can.

As an example of the embodiment of the filler for civil engineering work, there can be cited one in which the rigid foamable resin is a rigid foamed polyurethane foam.
Here, the rigid foamed polyurethane foam is obtained, for example, by mixing a liquid material containing a polyisocyanate component and a liquid material containing a polyol component and a foaming agent (such as water). The filler for civil engineering work of the present invention can further include an aggregate (claim 3). By including the aggregate, the strength of the entire filler can be improved. In the filler for civil engineering work of the present invention, the content of the hard foamable resin is usually 10 to 90% by volume (Claim 4).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As a rigid foamable resin used as a material for a filler for civil engineering work of the present invention, for example, a rigid foamed polyurethane foam may be mentioned. The rigid foamed polyurethane foam is obtained, for example, by mixing a liquid substance containing a polyisocyanate component and a liquid substance containing a polyol component and a foaming agent.

Here, as the polyisocyanate component, for example, 2,4-tolylene diisocyanate, 2,2
Aromatic diisocyanates such as 6-tolylene diisocyanate, crude tolylene diisocyanate, methylene diphenyl diisocyanate, and crude methylene diphenyl diisocyanate; 4,4 ', 4 "-triphenylmethane triisocyanate, 2,4,6-tolylene triisocyanate Aromatic triisocyanates; aromatic tetraisocyanates such as 4,4'-dimethyldiphenylmethane-2,2'-5,5'-tetraisocyanate; aliphatic isocyanates such as hexamethylene-1,6-diisocyanate; hydrogenated methylene Alicyclic isocyanates such as diphenyl diisocyanate; m-phenylene diisocyanate;
Naphthylene-1,5-diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, 4,4'-biphenylenediisocyanate, 3,3'-dimethoxy-
4,4'-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, and the like. As the polyisocyanate component, one type may be used alone, or two or more types may be used in combination.

The polyol component includes, for example, polyether polyol, polyester polyol, castor oil and the like. The molecular weight of the polyol component may be either low molecular weight or high molecular weight. The polyol component generally has a hydroxyl value of 20 to 600 mg KOH / g.

Here, as the polyether polyol, a compound having a structure in which an alkylene oxide is added to an active hydrogen-containing compound such as a polyhydric alcohol, a polyhydric phenol, an amine, or a polycarboxylic acid is used. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, pentaerythritol, and sucrose. Examples of polyhydric phenols include pyrogallol,
Polyphenols such as hydroquinone, bisphenol A
And the like, and condensates of phenol and formaldehyde. Examples of the amines include alkanolamines such as ammonia, monoethanolamine, diethanolamine, triethanolamine, and isopropanolamine; alkylamines having 1 to 22 carbon atoms;
Aliphatic amines such as alkylene diamines having 2 to 6 carbon atoms; aromatic amines such as aniline, phenylenediamine and diaminotoluene; alicyclic amines such as isophorone diamine cyclohexylene diamine; and heterocyclic amines. Can be Examples of the polycarboxylic acid include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and maleic acid; and aromatic polycarboxylic acids such as phthalic acid, terephthalic acid, and trimellitic acid. Examples of the alkylene oxide added to the active hydrogen-containing compound include propylene oxide, ethylene oxide, butylene oxide, tetrahydrofuran and the like.

Examples of the polyester polyol include a condensed polyester polyol obtained by reacting a polyhydric alcohol and a carboxylic acid, and a polyester polyol obtained by ring-opening polymerization of a lactone.

The amounts of the polyisocyanate component and the polyol component used are preferably such that the isocyanate index represented by the NCO / OH equivalent ratio is 0.8 to 1.2.

Examples of the foaming agent include water, chlorofluorocarbon, hydrofluorocarbon, hydrochlorofluorocarbon and the like. The foaming action of water is based on the fact that water reacts with the polyisocyanate component to generate carbon dioxide. The amount of the foaming agent used is about 0.1 to 40% by weight in the total amount of the polyisocyanate component, the polyol component and the foaming agent.

The components for forming the rigid foamed polyurethane foam further include, if necessary, a urethanization catalyst such as triethylenediamine and dimethylethanolamine; a foam stabilizer such as dimethylsiloxane-polyether block copolymer; and ethylene glycol and the like. Crosslinking agent; a viscosity reducing agent obtained by swelling a clay mineral such as montmorillonite in a solvent such as benzene can be used.

The rigid urethane foam may be prepared by another method, for example, a liquid material containing an isocyanate prepolymer component obtained by previously reacting the above-mentioned polyisocyanate component and a polyol, and a liquid material containing a polyol component and a foaming agent. It can also be obtained by reacting with a substance.

As the rigid foamed polyurethane foam,
There are various types. For example, the specific gravity is 0.04 (the specific gravity of the stock solution is 1.2 and the expansion ratio is 30), the compressive strength is 0.2 MPa, and the specific gravity is 0.06 (the specific gravity of the stock solution is 1.2 and the expansion ratio is 20).
) With a compressive strength of 0.5MPa, specific gravity of 0.08 (the specific gravity of the stock solution is 1.2, the expansion ratio is 15 times), and the compressive strength is 0.7MPa
And so on. These are marketed, for example, under the trade name of “Set Form” (registered trademark) by Nisshinbo Industries, Ltd. as a manufacturer. In the present invention, the type of the rigid foamed polyurethane foam may be appropriately selected according to the application.

Examples of the cement used as a material for the filler for civil engineering work of the present invention include portland cements such as ordinary portland cement, early-strength portland cement, ultra-high-strength portland cement, blast furnace cement, fly ash cement, silica cement and the like. Is mentioned.

The aggregate used as the material of the filler for civil engineering work of the present invention includes fine aggregates such as sea sand, river sand, mountain sand and crushed sand, and coarse aggregates such as sea gravel, river gravel and mountain gravel. Is mentioned. The amount of aggregate is about 0 to 500 parts by weight of fine aggregate and about 0 to 800 parts by weight of coarse aggregate per 100 parts by weight of cement. As materials for backfilling and landfilling, it is preferable to mix 100 to 500 parts by weight of fine aggregate and 100 to 800 parts by weight of coarse aggregate per 100 parts by weight of cement. The amount of kneading water is usually about 35 to 55% in terms of water cement.

The proportion of the hard foamable resin in the filler for civil engineering work of the present invention is 10 to 90% by volume. If the amount of the hard foaming resin is less than 10% by volume, the purpose of reducing the amount of cement or aggregate used cannot be sufficiently achieved, and crushing at the time of repair becomes difficult. 90% by volume of hard foaming resin
If it exceeds 3, the required compressive strength and specific gravity may not be obtained.

It is preferred to use various admixtures with the cement. As an admixture, AE agent, water reducing agent, AE
Water reducing agents, high performance water reducing agents, high performance AE water reducing agents, and the like. By blending the admixture, effects such as improvement of workability (workability) based on a ball bearing effect of air bubbles and reduction of a unit water amount can be obtained.

Next, a method for forming the filler for civil engineering work of the present invention will be described. First, after estimating the volume of the cavity (place to be filled) to be filled, the amount of each material used is determined in consideration of the expansion ratio of the hard foamable resin. At this time, when the specific gravity must be adjusted to a value larger than 1 for construction in water, or when used as backfill material in open-cutting work (subway, common ditch, etc.), the compressive strength must be more than a certain value ( For example, when the pressure must be set to 0.6 MPa or more, the material and the use amount may be determined so as to satisfy these conditions.

Next, a kneaded mixture of cement, water, and aggregate, and a stock solution of a hard foaming resin (for example, a liquid containing a polyol component and a liquid containing a polyisocyanate component, are mixed. , Which foams and hardens in this way) at the same time or alternately. After casting, the stock solution of the hard foaming resin foams to form a hard foaming resin having a predetermined strength, and coexists with the hard foaming resin to form a hardened concrete (ie, cement, aggregate). , Etc.) is formed. That is, a hard foamable resin is mixed in the hardened concrete, or a hardened concrete is mixed in the hard foamed resin. Therefore, as compared with the case where the hard foamable resin is used alone, the compressive strength and specific gravity of the entire filler are increased, and the filler has properties suitable as a backfill material and the like.

The filler for civil engineering work of the present invention can be used in combination with a conventionally used backfill soil (earth and sand). In order to use them together, for example, the filler for civil engineering work of the present invention and the conventional backfill soil (earth and sand) may be alternately stacked so as to be separate layers. In this case, it is preferable to use, as the backfill soil, one having a property in which the compaction phenomenon is unlikely to occur.
Even when backfill soil is used in this way, the use of the filler of the present invention makes it difficult for moisture in the backfill soil to move, thereby making it difficult for the compaction phenomenon to occur.

The filler for civil engineering work of the present invention is used, for example, in applications as shown in FIGS. FIG. 1 shows a concrete body 2 in which a subway train passage is formed in a cavity cut below a road 1 and a filler 3 of the present invention.
FIG. 5 is a cross-sectional view showing a state in which a backfill soil and a backfill soil 4 are sequentially installed or filled from below to above. The thickness of the backfill soil 4 is, for example, about 1.2 m. FIG. 2 is a cross-sectional view showing a state in which the filler 7 of the present invention and the backfill soil 8 are filled below the road surface 6 of the train in the subway tunnel 5. FIG. 3 is a cross-sectional view showing a state in which a filler 11 of the present invention is filled in a concrete pipe 10 in which a number of conduits 9 are accommodated.

An example of the composition of the filler for civil engineering work of the present invention is as follows. [Formulation Example 1] As a material, ordinary Portland cement 10
0 parts by weight, 300 parts by weight of coarse aggregate (particle size: 5 to 10 mm), 200 parts by weight of fine aggregate (particle size: 0.5 to 1.5 mm), 40 parts by weight of water, and 10 parts by weight of a hard urethane foam stock solution are used. As the stock solution of the rigid foamed polyurethane foam, one having a specific gravity of 1.2, an expansion ratio of 30, and a compression strength of a cured body after foaming of 0.2 MPa is used. The specific gravity of the filler of the present invention obtained using these materials is 1.2.

[Formulation Example 2] As materials, 100 parts by weight of ordinary Portland cement, 400 parts by weight of coarse aggregate (particle size 5 to 10 mm), 300 parts by weight of fine aggregate (particle size 0.5 to 1.5 mm), and 40 parts by weight of water Parts, 35 parts by weight of a stock solution of rigid urethane foam. In addition,
As a stock solution of rigid foamed polyurethane foam, specific gravity is 1.
2.The expansion ratio is 15, and the compressive strength of the cured body after foaming is 0.7MPa
Use The specific gravity of the filler of the present invention obtained using these materials is 1.1. Further, the compressive strength of the filler is 0.7 MPa or more, and satisfies the condition of 0.6 MPa or more required for the physical properties of the backfill soil.

[0028]

Since the filler for civil engineering work of the present invention contains a hard foaming resin and cement, it does not cause a compaction phenomenon as seen in the conventional backfill soil, and has a light weight and a large strength. As a filler that can be easily crushed at the time of repair or the like, it can be suitably used for applications such as backfilling, landfilling, and filling in pipelines.

Further, the strength of the filler of the present invention can be adjusted to a desired size by selecting the type of the hard foamable resin according to the use of the filler of the present invention. For example, when used as backfill material under roads with heavy traffic, large compressive strength (for example, 0.6 MPa or more)
When a hard foaming resin that exhibits high compressibility is selected and used as a filler that does not require a large compressive strength such as filling in a pipeline, a relatively low compressive strength (for example, 0.2 to 0.3MP
What is necessary is just to select the hard foaming resin which expresses a).

The specific gravity of the filler of the present invention can be adjusted to a desired size by adjusting the amount of the stock solution of the hard foaming resin which expands about 15 to 30 times. For example, in the case where the filler of the present invention is immersed in water for landfill, if the specific gravity of the filler of the present invention is adjusted to a value slightly larger than 1 (for example, 1.1 to 1.3), cement or cement may be used. Aggregate usage can be minimized.

The hard foaming resin is chemically stable, does not harm the surrounding environment, and has excellent durability. The hard foaming resin is also easily crushed, and by being included in the filler of the present invention, repair work after the construction (formation of a cavity again by crushing the filler) is facilitated.

Further, the filler of the present invention is formed by reacting spontaneously and expanding by simply mixing the respective materials at the work site. Therefore, the construction work is easy, and the construction period can be shortened and the construction cost can be reduced.

[Brief description of the drawings]

FIG. 1 shows a concrete body in which a subway train passage is formed inside, a filler material of the present invention, and a backfill soil in a cavity cut down below a road, from bottom to top in order from the bottom. It is sectional drawing which shows the state which was installed or filled.

FIG. 2 is a cross-sectional view showing a state in which a filler of the present invention and backfill soil are filled below a road surface of a train in a subway tunnel.

FIG. 3 is a cross-sectional view showing a state in which a filler according to the present invention is filled in a concrete pipe containing a large number of electric conduits therein.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Road 2 Concrete body 3,7,11 Filler 4,8 Backfill soil 5 Tunnel 6 Road surface 9 Conduit pipe 10 Concrete pipe

Claims (4)

[Claims] 1. A filler for civil engineering work, comprising a hard foamable resin and cement. 2. The filler for civil engineering work according to claim 1, wherein the rigid foamable resin is a rigid foamed polyurethane foam. 3. The filler for civil engineering work according to claim 1, further comprising an aggregate. 4. The filler for civil engineering work according to claim 1, wherein the content of the hard foamable resin is 10 to 90% by volume.